1. Field of the Invention
The present invention relates to auto tools changes, and more particularly, to an auto tools change with space allowance during the tool pushing process of the spindle. The present invention is able to accurately clamp the tool and prevent the spindle from being damaged during the overtravel of tool ramming.
2. Description of the Related Art
Known CNC tool machines are usually provided with a tool magazine and an auto tools change for automatically changing a tool stored in the tool magazine with a tool on the spindle of the tool machine through a tools change arm, thereby meeting different demand of processing, achieving the effect of process automation and acceleration.
However, regarding an ordinary tool machine, a tool is tightly drawn and fastened in a taper bore of the tool machine through a tool drawing rod and a claw, wherein temperature of the tool rises due to the rotation or the cutting action of the spindle during operation. As a result, the tool seat of the tool is overly stuck in the taper bore. When the tools change arm tends to withdraw the tool, the force simply produced by the tool drawing rod of the spindle pushing through the claw is not enough, so an additional process of ramming the tool seat for separating the tool seat and the taper bore is needed, whereby the tools change arm is able to withdraw the tool.
Furthermore, for enabling the tools change arm to accurately clamp the tool, the tools change arm is needed to be maintained at a correct height for rotating to clamp the tool, wherein the allowance of movement thereof is considerably limited. As a result, when the tool drawing rod rams the tool seat, due to the fixed height of the tools change arm for clamping the tool, the tools change arm has to bear the ramming force, causing the tools change arm to be deformed. Also, because the ramming force focuses on the junction of the tool drawing rod and the tool seat, damage of the tool drawing rod and the tool seat occurs possibly.